Mechanically expansible element



July 25, 1933- R. E. LYFORD MECHANICALLY EXPANSIBLE ELEMENT Filed July 13, 1929 2 Sheets-Sheet 1 Ewen/i0?" /?0b er/ 597 4.

July 25, 1933. R. E. LYFORD MECHANICALLY EXPANSIBLE ELEMENT 2 Sheets-Sheet 2 Filed July 13, 1929 Y 15 other.

Patented July 25 UNITED T S.

ROBERT E. LYFoRn'oF CHICAGO, ILLINOIS, ASSIGNOR TO INTERNATIONAL rmnvnsuuan I coMrANY, A ooRroRAr oN on NEW JERSEY mEoHaNIoALLY nXPn sIBLE ELEMENT Application filed July 13,

This invention relates to elementseapableof being altered in one dimension by the variation of pressure on the element applied in the direction of another dimension, and to 5 devices embodying such elements. 7

V Moreparticularly, the invention relates to elements adaptable for use in devices having two contact surfaces or twosimilar surfaces which may be brought intocontact. The "invention is particularly applicable. to devices having two elements with surfacesof revolution, such as cones'or cylinders, which are mounted for rotation, reciprocation, or contraction or expansion with respect-to each The elements may be mounted so thatthe surfaces contact and may be lubricated as in friction reducing bearings, or may be frictionally'engageable as in brakes and clutches. The elements may also be 20 mounted to provide a variable, annular;-

space between two stationary elements.

The object of the invention isto devise and construct elements which will function or, for the purposes above set forth and. for similar purposes.

construct anelement capable of dimensional alteration when subject to pressure. Another object is to construct elements for surface contact devices capable of being adjusted to desired engagingpressure or to provide thedesired clearance.

I attain the above objects by the nove construction hereinafter described in detail of comparatively narrow bands or rings, or

" elementswith portions having'surface's similar thereto. l The bands or similar elements are corrugated or undulated. The general location of the corrugations pressure is released, the natural resiliency of the element acts to contract it to the norcumferential pressure would contract such The principal object is to:

. 0]], undulations can best be defined by conm'al, position. It is also obvious that cir-v 1929. Serial Nofaiaiea:

an element, if appliedlonthe outsidey'and expand the element,if the be applied on the inside.

pressure were to Suitable-members may contact with or be I rigidly attached to the loops of the undulat provided for applying pressure to these .56 i ing bands or similar elements, andmeans are members. In some modifications ofthe in-j I vention, the undulating bands, or like; members having the, same characteristics, may be compressed or expanded before beingfpositioned'in engagement withthe cooperating members. In this case, the resiliencyofthe undulating member may serve to maintain the proper radial. relationship without any additional pressure means.

Although this inventionfis applicable to any closed band-like elements, it is particularly adaptable to such elements having surfaces of revolution geometrically defined, suchas'elements havingconical or cylindrical. surfaces. In the drawings and description, only cylindrical forms have been'shown I and described.

The drawings' show the? invention Qembodied n a brake. In these drawings,

a side elevation, partly in brake shown inFigures 1 2, and 8.'

As SllOWIl'lIl the drawings, an axle housing 1 l is threaded at the outer end 2 and is pro, 1 I

videdwith a flange 3 spaced .jfrom the end The housing is also. provided With a 's houl der 4 and spline :grooves 5. A plate 6Jis rigidly secured to the housingby engage inent'with splines" 7.. The plate 6 is held/ in position against the shoulder-4' by a'nut 8 on'the threaded end of the housing.

A plate 9 is splined on the housing for longitudinal movement with respect there to between the plate6 and the flange 3. y

The plate 9 is provided with a series of cam surfaces 10 adjacent the axle housing 1. An annular actuating collar 11 ispositioned between the flange 3 and the plate 9 and is provided with a series of cam surfaces'12 mating with the cam surfaces on the plate. The actuating collar is provided with an extension 13 to which an operating rod 14 is attached. t

The contact assembly 14 is made up of.

, one, or more annular band-like elements '15,

. terial as to be inherently resilient.

which are corru 'ated or undulate'd circumferentia'lly in the direction-of the axis of the housing. The elements 15 are of such a ma- The use to which the device is to be put, the clearance between tl e contact assembly and the surrounding drumfthe pressure available to act on the elements, and thesize ofthe'.

corrugations relative to the thickness of the individual elements are some of the factors determining the choice "of material. Thin steel bands ofa considerable number mi ht jacent the plate 6.

be used. Rubber or rubber .fabricor com position of amucli greater thickness in proportion to the size of the corrugation may be used.

ments would be used for brakes or clutches,-

Asbestos fabric or molded'eleas this material withstands the heat. -'Any material having the required resiliency and other. necessary properties may. be utilized.

Pins 16 entend through the elements 15 and into aligned slots 17 in the plates 6 and 9. Springs 18 maybe pOS1lZ1011BClO11'tl18 ends the pins 16 which emerge from the low parts OI dGPITQSSlOIlS of the undulations in elements 15. As shown in the particular device illustratedin the drawings; the pins 16 extend through the undulated members 15 at the points where the depressions on said members are adjacentthe plate'9. It may be found desirable to provide projecting members 19 on the plate 6 to provide seats for springs 20 positioned to engage the de-' alone on the elements 15, which are ad A drum 21 mounted for rotation with respect to the housing surrounds the contact assembly 14 in close proximity thereto. As

shown in Figure '1, the drum may be attached to a wheel 22 mounted on an axle 23 rotatable in the housing 1.

'In the operation of the device, the plate 9 is moved towards the plate 6 by operating" the actuating collar 11, thereby exerting an axial pressure on the contact assembly 14. In the case ofa brake or clutch, the assembly 14:. may be made up of a molded composition such as is commonly used for that purpose, or it may be composedof metallic bands shaped as shown. V

Compression on opposite sides of the con nal form, thereby reducing their circumier 'ence and disengaging the drum 21.

When the contact assembly 1 1 is com posed ofmaterial such as woven brake lining, the resiliency of which may not be great enough to suiliciently reduce the circumter ence upon release of the axial pressure, springs, such as shown at 18yand 20..inay be provided. for that purpose.

- In Figure 3, thepins 16 are shown at the bottom ofthe slots 17. In this position the elements 15 are in the: contracted position with respect tothe drum 21; When the contact assembly 14:is expanded, the pins 16 move outwardly in'the slotsl'Z. It willbe noted that the contact member is therefore, self-centering with respect to the drum 21. Although I have illustrated and described my invention as embodied in a friction contact device of the type ore inarily, employed in brakes it has a wide field'ot use. All of the uses to'which it may be put are contemplated, and the inventionis limited only by the scopeof the appended. claims.

What is claimed is l. A surface contacting device comprising av member having a surface of revolution, a

second member having similar surrace po-.

sitioned to engage the first mentioned.sur-

face, thesurface of the second member being comparatively narrow and undulated inthe direction of the/axis of the surface, and means to alter the circumference of the undulated surface.

- 2. A surface contacting device comprising a member having a surface ofirevolution, a second member having a similar. surfacepositioned to engage .the'firstm'entionedsur-' face, the surface of the second memberfbeing comparatively narrow and undulated 1n the direction 1 of the axis of'the surface, andmeans to exert variable pressures aXiallyon the member having the 'undulated' surface.

wherebythe circumference of said surface is altered. ROBERT E. LYEORD. 

